With the decrease of the semiconductor integrated circuit in size, the supply voltage becomes lower and lower, and charge pumps, such as power management integrated circuits, non-volatile memories, switched capacitor circuits, operational amplifiers, transformers, SRAM, LCD drivers, RF antenna switch controllers, are becoming more widely used. An example of the use of the electric circuits of charge pumps is to provide a negative voltage source, which voltage is lower than that of the ground, to control the operation of the RF antenna switches.